comput the input for vaccum when setting remove_vaccum_contribution

[github-actions]

Idealy, the input for vaccum should be computed;
we consider it as always zero for convenience.
Needs a compute_input_stats for vaccum passed from the
descriptor.

Line: 316

deepmd-kit//deepmd/dpmodel/fitting/general_fitting.py

Lines 313 to 323 in 4d347ec

	)
	xx = descriptor
	if self.remove_vaccum_contribution is not None:
	# TODO: comput the input for vaccum when setting remove_vaccum_contribution
	# Idealy, the input for vaccum should be computed;
	# we consider it as always zero for convenience.
	# Needs a compute_input_stats for vaccum passed from the
	# descriptor.
	xx_zeros = np.zeros_like(xx)
	else:
	xx_zeros = None